That number has been seared into the brains of political observers dissecting the crucial 2018 congressional midterms. 23 is the number of House seats Democrats must win to gain control of the House of Representatives. Currently, the nation’s leading political prognosticators, Larry Sabato’s Crystal Ball, Nate Silver’s FiveThirtyEight and The Cook Political Report, think that is more likely to happen than not.

Most believe that if it happens, Pennsylvania will play a major role. If national Democrats are to regain power, the road runs through Pennsylvania.

This prominent role for Pennsylvania voters is a new one in midterm elections. Usually a “battleground state” in presidential elections, the state has been more of an asterisk in the midterms. Until recently the state’s congressional map overwhelmingly favored Republican candidates, allowing the GOP to capture 13 of the state’s 18 congressional seats.

But that changed radically when a redrawn congressional map put into effect by the state Supreme Court made Pennsylvania’s congressional districts much more competitive.

As the traditional Labor Day start of campaigning begins, a clear pattern now exists across the state of “safe” Republican seats, “safe” Democratic seats, and seats that could go either way.

For Democrats, their deepest strength lies in the southeastern part of the state, including the city of Philadelphia and its suburban counties, Bucks, Montgomery, Delaware and Chester. Republican strength is located in the rural and small-town portions of Pennsylvania, concentrated in the western and southcentral parts of the state. All together Republicans appear to have nailed down some six seats, while Democrats look solid in another six seats, and the remaining six seats look competitive.

Safe Republican Seats –

These characteristically are seats with a large majority of registered Republican voters. They typically were carried by Donald Trump in 2016 by wide margins. Most are in central and western PA.

PA 9th – This is an open seat but the 85th most Republican seat in the nation. The Republican candidate, Dan Meuser, is virtually guaranteed a win. PA 12th – Incumbent Tom Marino is a solid favorite in what is the 57th most Republican district in the nation.PA 13th – The Republican candidate, John Joyce, is an overwhelming favorite in this race in another solidly Republican district, labeled the 27th most Republican in the nation.PA 14th – This is another strong Republican district considered to be the 92nd most Republican in the nation. Republican Guy Reschenthaler should win easily.PA15th – This is the 38th most Republican district in the nation. Republican candidate, Glenn Thompson, already an incumbent from a superseded district, will win comfortably.PA 16th – The district is considered the 100th most Republican district in the nation, where Republican candidate and incumbent Mike Kelly should win.

Safe Democrat Seats –

These characteristically are congressional districts with a large majority of registered Democratic voters in districts carried easily by Hillary Clinton in 2016. Most are in eastern Pennsylvania.

PA 2nd – This overwhelming Democratic district, partly in the city of Philadelphia, is the 44th most Democratic district nationally. Brendan Boyle, the Democrat incumbent, should win with at least 75 percent of the vote.PA 3rd – This is the third most Democratic district in the nation and incumbent Dwight Evans won his previous race with some 90 percent of the vote. He will do so again in 2018.PA 4th – This mostly affluent Montgomery County district is rated the 150th most Democratic in the nation. Democratic candidate Madeleine Dean should win with 60 percent or more of the vote.PA 5th – Democrat Mary Gay Scanlon will win this Delaware County district easily. Considered the 103rd most Democratic district nationally, it is one that Clinton won decisively in 2016.PA 6th – Democrat Chrissy Houlahan should win this district formerly represented by Republican Ryan Costello, who is not running for reelection. It is one of the Republican held districts Clinton won and has been intensely targeted by Democrats in 2018.PA 18th – Rated as the most 106th most Democratic district nationally, Democrat Mike Doyle, the most senior member of the Pennsylvania delegation, is unopposed for reelection.

The Toss-up Seats

These districts are scattered around the state largely away from the eastern Democratic strongholds or the western Republican dominated areas.

PA 1st – Republican incumbent Brian Fitzpatrick is favored here to eke out a narrow victory in this Bucks County district with a slight Republican lean. A substantial blue wave would, however, endanger him.PA 7th – Democrat Susan Wild is probably slightly ahead in a district with a small Democratic tilt. Clinton defeated Trump by one point here. Democratic turnout this year could determine the outcome.PA 8th – This is one of 13 Democratic held districts nationally won by Trump in 2016. It leans slightly Republican in voter registration. However, Democratic incumbent Matt Cartwright is very popular and should win if any sizable Democrat wave materializes.PA 10th – Incumbent Republican Scott Perry should win here, but redistricting put plenty of new Democratic voters in his district while his Democratic opponent George Scott is running a well-organized and financed campaign. Democratic turnout will matter here.PA 11th – Incumbent Republican Lloyd Smucker is considered vulnerable by some, but the district remains strongly Republican. This is another Pennsylvania district where it will take a substantial blue wave for the Republican to lose.PA 17th – This is one that Trump won narrowly. It also has a Republican incumbent (Keith Rothfus), and it’s the only district in the nation that pits two incumbents against one another. Democrat Connor Lamb is leading the race, but the district has a Republican tilt.

Most analysts believe Pennsylvania Democrats need to add a net of 3 -5 seats to change party control of Congress. In late summer 2018, this looks doable. But Republican hopes are far from forlorn. Barring any surprises, almost a third of these races are still in doubt